Herbicidal composition

ABSTRACT

To provide a high active herbicidal composition having a broad herbicidal spectrum. 
     A herbicidal composition comprising (a) nicosulfuron or its salt, (b) prosulfuron or its salt and (c) at least one herbicidal compound selected from the group consisting of mesotrione, bicyclopyrone, dicamba, dicamba ester, bromoxynil, bromoxynil ester and their salts.

TECHNICAL FIELD

The present invention relates to a herbicidal composition comprising (a)nicosulfuron or its salt (hereinafter referred to as compound A), (b)prosulfuron or its salt (hereinafter referred to as compound B) and (c)at least one herbicidal compound selected from the group consisting ofmesotrione, bicyclopyrone, dicamba, dicamba ester, bromoxynil,bromoxynil ester and their salts (hereinafter referred to as compoundC).

BACKGROUND ART

Patent Document 1 discloses a herbicidal composition comprising compoundB and a specific known herbicide. Further, Patent Document 2 discloses aherbicidal composition comprising2-[4-(methylsulfonyl)-2-nitrobenzoyl]-1,3-cyclohexanedione and aspecific known herbicide.

Further, Patent Document 3 discloses a herbicidal composition comprisingbicyclopyrone and a specific known herbicide.

However, any of the above Patent Documents does not disclose aherbicidal composition comprising a specific combination of compound A,compound B and compound C as herbicidally active ingredients of thepresent invention, and does not specifically disclose a remarkablesynergistic effect obtained by the combination.

PRIOR ART DOCUMENTS Patent Documents

Patent Document 1: WO93/21772

Patent Document 2: WO97/48276

Patent Document 3: EP1842426

DISCLOSURE OF INVENTION Technical Problem

At present, many herbicidal compositions have been developed and used,but there are a variety of types of undesired plants represented byweeds to be controlled. Further, undesired plants having loweredsensitivity to herbicides (herbicide-resistant weeds) emerged, and insome applications, practically, herbicides have only insufficienteffects.

The object of the present invention is to provide a high activeherbicidal composition having a broader herbicidal spectrum, and amethod for controlling undesired plants or inhibiting their growth usingit.

Solution to Problem

The present inventors have conducted extensive studies to solve theabove problems and as a result, found that unexpectedly excellentherbicidal effects can be obtained by combination of specific compoundA, compound B and compound C which are herbicidally active ingredientsof the present invention, as compared with a case where the respectivecompounds are applied individually or two compounds are used incombination (for example, compound A and compound C are used incombination), and accomplished the present invention.

That is, the present invention relates to a herbicidal compositioncomprising compound A, compound B and compound C as herbicidally activeingredients.

The present invention further relates to a method for controllingundesired plants or inhibiting their growth, which comprises applying aherbicidally effective amount of the herbicidal composition to theundesired plants or to a place where they grow.

The present invention further relates to a method for controllingundesired plants or inhibiting their growth, which comprises applying aherbicidally effective amount of compound A, a herbicidally effectiveamount of compound B and a herbicidally effective amount of compound C,to the undesired plants or to a place where they grow.

Advantageous Effects of Invention

The herbicidal composition of the present invention is capable ofcontrolling a wide range of undesired plants emerging in agriculturalfields or non-agricultural fields. It has a remarkable herbicidalactivity when a composition comprising compound A and compound B, andcompound C as a specific third herbicidally active ingredient are usedin combination. It represents a synergistic effect i.e. a herbicidaleffect higher than the mere addition of the herbicidal effect of thecombination of compound A and compound B and the herbicidal effect ofthe third herbicidally active ingredient.

That is, the herbicidal composition of the present invention can beapplied at a low dose as compared with a case where the respectiveactive ingredients are applied individually. Thus, it is effective toreduce the environmental load on an area where the composition isapplied or a surrounding area thereof.

When the herbicidal activity in a case where two active ingredients arecombined, is larger than the simple sum of the respective herbicidalactivities of the two active ingredients (the expected activity), it iscalled a synergistic effect. The activity expected by the combination oftwo active ingredients can be calculated as follows (Colby S. R.,“Weed”, vol. 15, p. 20-22, 1967).E ¹=(α+β)−(αβ)/100

Similarly, the activity expected by the combination of three activeingredients can be calculated as follows.E ²=(α+β+γ)−(αβ+αγ+βγ)/100+(αβγ)/10,000where

α: growth inhibition rate when treated with x (g/ha) of herbicide X,

β: growth inhibition rate when treated with y (g/ha) of herbicide Y,

γ: growth inhibition rate when treated with z (g/ha) of herbicide Z,

E¹: growth inhibition rate expected when treated with x (g/ha) ofherbicide X and y (g/ha) of herbicide Y.

E²: growth inhibition rate expected when treated with x (g/ha) ofherbicide X, y (g/ha) of herbicide Y, and z (g/ha) of herbicide Z.

That is, when the actual growth inhibition rate (measured value) islarger than the growth inhibition rate by the above calculation(calculated value), the activity by the combination can be regarded asshowing a synergistic effect.

The herbicidal composition of the present invention shows a synergisticeffect when calculated by the above formula.

DESCRIPTION OF EMBODIMENTS

As for compound A, nicosulfuron (common name) is2-(4,6-dimethoxypyrimidin-2-ylcarbamoylsulfamoyl)-N,N-dimethylnicotinamide.

As for compound B, prosulfuron (common name) is1-(4-methoxy-6-methyl-1,3,5-triazin-2-yl)-3-[2-(3,3,3-trifluoropropyl)phenylsulfonyl]urea.

As for compound C, mesotrione (common name) is2-(4-mesyl-2-nitrobenzoyl)cyclohexane-1,3-dione.

As for compound C, bicyclopyrone (common name) is4-hydroxy-3-{2-[(2-methoxyethoxy)methyl]-6-(trifluoromethyl)-3-pyridylcarbonyl}bicyclo[3.2.1]oct-3-en-2-one.

As for compound C, dicamba (common name) is a compound disclosed in ThePesticide Manual Sixteenth Edition, pages 319 to 321. Its ester or asalt thereof may, for example, be dicamba-methyl, dicamba-butotyl,dicamba-diglycolamine, dicamba-dimethylammonium, dicamba-diolamine,dicamba-isopropylammonium, dicamba-potassium or dicamba-sodium.

As for compound C, bromoxynil (common name) is a compound disclosed inThe Pesticide Manual Sixteenth Edition, pages 131 to 134. Its ester or asalt thereof may, for example, be bromoxynil-heptanoate,bromoxynil-octanoate or bromoxynil-potassium.

The salt included in compound A, compound B and compound C may be anysalt so long as it is agriculturally acceptable. Examples thereofinclude alkali metal salts such as a sodium salt and a potassium salt;alkaline earth metal salts such as a magnesium salt and a calcium salt;ammonium salts such as a monomethylammonium salt, a dimethylammoniumsalt and a triethylammonium salt; inorganic acid salts such as ahydrochloride, a perchlorate, a sulfate and a nitrate, and organic acidsalts such as an acetate and a methanesulfonate.

The mixing ratio of the respective compounds in the present inventioncannot generally be defined, as it varies depending upon variousconditions such as the type of the formulation, the weather conditions,and the type and the growth stage of the undesired plants. The mixingratio of compound A to compound B is, for example, from 75:1 to 1:15,preferably from 40:1 to 1:5 by the weight ratio. Further, the mixingratio of compound A to compound C is, for example, from 15:1 to 1:100,preferably from 4:1 to 1:50 by the weight ratio.

In a case where compound C is mesotrione or its salt, the mixing ratioof compound A to compound C is preferably from 4:1 to 1:15 by the weightratio.

By using the combination of compound A and compound B and furthermesotrione in combination in a mixing ratio of compound A to mesotrioneof from 4:1 to 1:15, particularly excellent effects (for example, asynergistic effect) will be obtained as compared with another mixingratio.

In a case where compound C is bicyclopyrone or its salt, the mixingratio of compound A to compound C is preferably from 4:1 to 1:40 by theweight ratio.

By using the combination of compound A and compound B and furtherbicyclopyrone in combination in a mixing ratio of compound A tobicyclopyrone of from 4:1 to 1:40, particularly excellent effects (forexample, a synergistic effect) will be obtained as compared with anothermixing ratio.

In a case where compound C is dicamba, its ester or a salt thereof, themixing ratio of compound A to compound C is preferably from 2:1 to 1:40by the weight ratio.

By using the combination of compound A and compound B and furtherdicamba, its ester or a salt thereof in combination in a mixing ratio ofcompound A to dicamba, its ester or a salt thereof of from 2:1 to 1:40,particularly excellent effects (such as a synergistic effect) will beobtained as compared with another mixing ratio.

In a case where compound C is bromoxynil, its ester or a salt thereof,the mixing ratio of compound A to compound C is preferably from 1:1 to1:50 by the weight ratio.

By using the combination of compound A and compound B and furtherbromoxynil, its ester or a salt thereof in combination in a mixing ratioof compound A to bromoxynil, its ester or a salt thereof of from 1:1 to1:50, particularly excellent effects (such as a synergistic effect) willbe obtained as compared with another mixing ratio.

The herbicidally effective amounts of compounds A, B and C cannotgenerally be defined, as they vary depending upon various conditionssuch as the mixing ratios of the respective compounds, the type of theformulation, the weather conditions, and the type and the growth stageof the undesired plants.

For example, compound A is applied in an amount of from 5 to 150 g/ha,preferably from 10 to 100 g/ha, compound B is applied in an amount offrom 2 to 75 g/ha, preferably from 2.5 to 50 g/ha, and compound C isapplied in an amount of from 10 to 500 g/ha, preferably from 25 to 500g/ha.

In a case where compound C is mesotrione or its salt, the herbicidallyeffective amount of compound C is preferably from 25 to 150 g/ha.

In a case where compound C is bicyclopyrone or its salt, theherbicidally effective amount of compound C is preferably from 25 to 400g/ha.

In a case where compound C is dicamba, its ester or a salt thereof, theherbicidally effective amount of compound C is preferably from 50 to 400g/ha.

In a case where compound C is bromoxynil, its ester or a salt thereof,the herbicidally effective amount of compound C is preferably from 100to 500 g/ha.

The herbicidal composition of the present invention may be applied toundesired plants or may be applied to a place where they grow. Further,it may be applied at any time either before or after the emergence ofthe undesired plants.

Further, the herbicidal composition of the present invention may takevarious application forms such as soil application, foliar application,irrigation application, and submerged application.

Further, it can be applied to agricultural fields such as upland fields,orchards and paddy fields, and non-cropland such as ridges of fields,fallow fields, play grounds, golf courses, vacant lands, forests,factory sites, railway sides and roadsides.

The herbicidal composition of the present invention can control a widerange of undesired plants such as annual weeds and perennial weeds. Theundesired plants to be controlled by the herbicidal composition of thepresent invention may, for example, be specifically cyperaceae such assedge (Cyperus spp.) (such as purple nutsedge (Cyperus rotundus L.),smallflower umbrella sedge (Cyperus difformis L.), yellow nutsedge(Cyperus esculentus L.) or amur cyperus (Cyperus microiria Steud.)) orspikesedge (Kyllinga spp.) (such as green kyllinga (Kyllinga brevifoliaRottb. var. leiolepis)); gramineae such as barnyard grass (Echinochloaspp.) (such as barnyardgrass (Echinochloa crus-galli L.), earlywatergrass (Echinochloa oryzicola vasing.) or Japanese millet(Echinochloa utilis Ohwi et Yabuno)), crabgrass (Digitaria spp.) (suchas summergrass (Digitaria ciliaris (Retz.) Koel), large crabgrass(Digitaria sanguinalis L.), violet crabgrass (Digitaria violascens Link)or Jamaican crabgrass (Digitaria horizontalis Willd.)), goosegrass(Eleusine spp.) (such as goosegrass (Eleusine indica L.)), ryegrass(Lolium spp.) (such as italian ryegrass (Lolium multiflorum Lam.)),foxtail (Setaria spp.) (such as green foxtail (Setaria viridis (L.))),sorghum (Sorghum spp.) (such as johnsongrass (Sorghum halepense (L.)Pers.) or shattercane (Sorghum bicolor (L.) Moench.)), oat (Avena spp.)(such as wild oat (Avena fatua L.)), brome (Bromus spp.) (such asdrooping brome (Bromus tectorum L.) or japanese brome (Bromus japonicusThunb.)), meadowgrass (Poa spp.) (such as annual bluegrass (Poa annusL.)), foxtail grass (Alopecurus spp.) (such as blackgrass (Alopecurusmyosuroides Huds.), shortawn foxtail (Alopecurus aequalis Sobol. var.amurensis)), bermudagrass (Cynodon dactylon (L.) Pers.), panic grass(Panicum spp.) (such as guinea grass (Panicum maximum Jacq.) or fallpanicum (Panicum dichotomiflorum (L.) Michx.)), signal grass (Brachiariaspp.) (such as plantain signal grass (Brachiaria plantaginea (LINK)Hitchc.), palisade signal grass (Brachiaria decumbens Stapf) ormauritius signal grass (Brachiaria mutica (Forssk.) Stapf)), paspalum(Paspalum spp.) (such as dallisgrass (Paspalum dilatatum Poir) orvasey's grass (Paspalum urvillei Steud.)), itchgrass (Rottboellia spp.)(such as itchgrass (Rottboellia cochinchinensis (LOUR.) W. D. CLAYTON)),or sandbur (Cenchrus spp.) (such as southern sandbur (Cenchrus echinatusL.)); scrophulariaceae such as persian speedwell (Veronica persicaPoir.) or corn speedwell (Veronica arvensis L.); compositae such asbeggar ticks (Bidens spp.) (such as hairy beggarticks (Bidens pilosaL.), devils berggarticks (Bidens frondosa L.) or Bidens biternata(Lour.) Merr. et Sherff, beggarticks (Bidens subalternans DC.)), hairyfleabane (Conyza bonariensis (L.) Cronq.), dandelion (Taraxacumofficinale Weber), horseweed (Conyza spp.) (such as canadian horseweed(Conyza canadensis (L.) Cronquist)), cocklebur (Xanthium spp.) (such ascommon cocklebur (Xanthium strumarium L.)), ragweed (Ambrosia spp.)(such as annual ragweed (Ambrosia artemisiifolia L.)), ragwort (Seneciospp.) (such as old-man-in-the-spring (Senecio vulgaris L.)); leguminosaesuch as rattlepod or rattlebox (Crotalaria spp.) (such as sunn-hemp(Crotalaria iuncea L.)), poison bean (Sesbania spp.) (such as rostratesesbania (Sesbania rostrata Bremek. & Oberm.) or sesbania pea (Sesbaniacannabina (Retz.) Pers.)), common lespedeza (Lespedeza striata (Thunb.)Hook. et Arn.), korean lespedeza (Kummerowia stipulacea (Maxim.) Makino)or white clover (Trifolium repens L.)); caryophyllaceae such as stickychickweed (Cerastium glomeratum Thuill.) or starwort (Stellaria spp.)(such as common chickweed (Stellaria media L.)); euphorbiaceae such asgarden spurge (Euphorbia hirta L.), threeseeded copperleaf (Acalyphaaustralis L.) or fireplant (Euphorbia heterophylla L.); plantaginaceaesuch as asiatic plantain (Plantago asiatica L.); oxalidaceae such ascreeping woodsorrel (Oxalis corniculata L.); apiaceae such as lawnpennywort (Hydrocotyle sibthorpioides Lam.); violaceae such as violet(Viola mandshurica W. Becker); iridaceae such as blue-eyedgrass(Sisyrinchium rosulatum Bicknell); geraniaceae such as carolina geranium(Geranium carolinianum L.); labiatae such as purple deadnettle (Lamiumpurpureum L.) or henbit (Lamium amplexicaule L.); malvaceae such asvelvetleaf (Abutilon theophrasti MEDIC.) or prickly sida (Sida spinosaL.); convolvulaceae such as ivy-leaved morningglory (Ipomoea hederacea(L.) Jacq.), common morningglory (Ipomoea purpurea ROTH), cypressvinemorningglory (Ipomoea quamoclit L.), Ipomoea grandifolia (DAMMERMANN)O'DONNELL, hairy merremia (Merremia aegyptia (L.) URBAN) or fieldbindweed (Convolvulus arvensis L.); chenopodiaceae such as goosefoot(Chenopodium spp.) (such as common lambsquarters (Chenopodium albumL.)); portulacaceae such as common purslane (Portulaca oleracea L.);amaranthaceae such as pigweed (Amaranthus spp.) (such as prostratepigweed (Amaranthus blitoides S. Wats.), livid amaranth (Amaranthuslividus L.), purple amaranth (Amaranthus blitum L.), smooth pigweed(Amaranthus hybridus L., Amaranthus patulus Bertol.), powell amaranth(Amaranthus powellii S. Wats.), slender amaranth (Amaranthus viridisL.), palmer amaranth (Amaranthus palmeri S. Wats.), redroot pigweed(Amaranthus retroflexus L.), tall waterhemp (Amaranthus tuberculatus(Moq.) Sauer.), common waterhemp (Amaranthus tamariscinus Nutt.), thornyamaranth (Amaranthus spinosus L.)), ataco (Amaranthus quitensis Kunth.)or roughfruit amaranth (Amaranthus rudis Sauer.)); solanaceae such asnightshade (Solanum spp.) (such as black nightshade (Solanum nigrumL.)); polygonaceae such as knotweed (Polygonum spp.) (such as spottedknotweed (Polygonum lapathifolium L.) or green smartweed (Polygonumscabrum MOENCH)); cruciferae such as flexuous bittercress (Cardamineflexuosa WITH.), or mustard (Sinapis spp.) (such as Charlock (Sinapisarvensis L.)); cucurbitaceae such as burcucumber (Sicyos angulatus L.);commelinaceae such as common dayflower (Commelina communis L.); rosaceaesuch as mock strawberry (Duchesnea chrysantha (Zoll. et Mor.) Miq.);molluginacea such as carpetweed (Mollugo verticillata L.); or rubiaceaesuch as false cleavers (Galium spurium var. echinospermon (Waft.) Hayek)or stickywilly (Galium aparine L.).

The herbicidal composition of the present invention is very useful inpractical application, and for example, the following cases may bementioned.

(1) It has a remarkable synergistic effect, and has a favorableherbicidal activity even if the doses of the respective compounds A, Band C are small, and accordingly the impact on the surroundingenvironment can be suppressed.

(2) A herbicidal composition having a long lasting herbicidal effecti.e. a long lasting residual activity, as compared with a case wherecompound A, compound B and compound C are applied individually, or twocompounds are used in combination (for example, compound A and compoundC are used in combination) may be provided.

(3) A herbicidal composition having a broad spectrum having high effectsagainst both gramineae and broad leaf weeds, as compared with a casewhere compound A, compound B and compound C are applied individually, ortwo compounds are used in combination (for example, compound A andcompound C are used in combination), may be provided.

(4) Annual and perennial gramineae such as Echinochloa spp., Digitariaspp., Setaria spp., Poa spp., Avena spp., Agropvron spp., Alopecurusspp., Eleusine spp., Rottboellia spp., Sorghum spp. and Panicum spp.,which are problematic as noxious weeds in agricultural fields,particularly corn fields, can be controlled.

(5) It has a high herbicidal activity also against weeds in late leafstage, such as weeds in 8-leaf stage, and particularly remarkable forgramineae.

(6) It has a favorable herbicidal activity against gramineae and broadleaf weeds either by foliar application or soil application.

(7) It has a high herbicidal activity against weeds having loweredsensitivity to ALS (acetolactate synthase) inhibitors, such ascyperaceae, amaranthaceae, compositae, cruciferae, caryophyllaceae, andgramineae.

(8) It has a high herbicidal activity against weeds having loweredsensitivity to PSII (photosystem II) inhibitors, such as gramineae,chenopodiaceae, amaranthaceae, solanaceae, malvaceae, compositae, andpolygonaceae.

(9) It has a high herbicidal activity against weeds having loweredsensitivity to 4-HPPD inhibitors, such as amaranthaceae.

In consideration of the application site of the herbicidal compositionor the type or growth state of the undesired plants, the herbicidalcomposition of the present invention may be mixed with or may be used incombination with other herbicides, fungicides, antibiotics, planthormones, insecticides, fertilizers, phytotoxicity-reducing agents,etc., in addition to the above active ingredients, without departingfrom the intention and the scope of the present invention, whereby moreexcellent effects and activities may sometimes be obtained.

Such other herbicides may, for example, be (1) those which are believedto exhibit herbicidal effects by disturbing hormone activities ofplants, (2) those which are believed to exhibit herbicidal effects byinhibiting photosynthesis of plants, (3) those which are believed to beconverted to free radicals by themselves to form active oxygen in theplant body and show rapid herbicidal efficacy, (4) those which arebelieved to exhibit herbicidal effects by inhibiting chlorophyllbiosynthesis of plants and abnormally accumulating a photosensitizingperoxide substance in the plant body, (5) those which are believed toexhibit herbicidal effects characterized by bleaching activities byinhibiting chromogenesis of plants such as carotenoids, (6) those whichexhibit strong herbicidal effects specifically to gramineous plants, (7)those which are believed to exhibit herbicidal effects by inhibiting anamino acid biosynthesis of plants, (8) those which are believed toexhibit herbicidal effects by inhibiting cell mitoses of plants, (9)those which are believed to exhibit herbicidal effects by inhibitingprotein biosynthesis or lipid biosynthesis of plants, and (10) thosewhich are believed to exhibit herbicidal effects by being parasitic onplants.

The herbicidal composition of the present invention may be prepared bymixing compound A, compound B and compound C, as active ingredients,with various agricultural additives in accordance with conventionalformulation methods for agricultural chemicals, and applied in variousformulations such as dusts, granules, water dispersible granules,wettable powders, tablets, pills, capsules (including a formulationpackaged by a water soluble film), water-based suspensions, oil-basedsuspensions, microemulsions, suspoemulsions, water soluble powders,emulsifiable concentrates, soluble concentrates or pastes. It may beformed into any formulation which is commonly used in this field, solong as the object of the present invention is thereby met.

At the time of the formulation, compound A, compound B and compound Cmay be mixed together for the formulation, or they may be separatelyformulated.

The additives to be used for the formulation include, for example, asolid carrier such as kaolinite, sericite, diatomaceous earth, slakedlime, calcium carbonate, talc, white carbon, kaoline, bentonite, clay,sodium carbonate, sodium bicarbonate, mirabilite, zeolite or starch; asolvent such as water, toluene, xylene, solvent naphtha, dioxane,dimethylsulfoxide, N,N-dimethylformamide, dimethylacetamide,N-methyl-2-pyrrolidone or an alcohol; an anionic surfactant such as asalt of fatty acid, a benzoate, a polycarboxylate, a salt ofalkylsulfuric acid ester, an alkyl sulfate, an alkylaryl sulfate, analkyl diglycol ether sulfate, a salt of alcohol sulfuric acid ester, analkyl sulfonate, an alkylaryl sulfonate, an aryl sulfonate, a ligninsulfonate, an alkyldiphenylether disulfonate, a polystyrene sulfonate, asalt of alkylphosphoric acid ester, an alkylaryl phosphate, a styrylarylphosphate, a salt of polyoxyethylene alkyl ether sulfuric acid ester, apolyoxyethylene alkylaryl ether sulfate, a salt of polyoxyethylenealkylaryl ether sulfuric acid ester, a polyoxyethylene alkyl etherphosphate, a salt of polyoxyethylene alkylaryl phosphoric acid ester, asalt of polyoxyethylene aryl ether phosphoric acid ester, a naphthalenesulfonic acid condensed with formaldehyde or a salt of alkylnaphthalenesulfonic acid condensed with formaldehyde; a nonionic surfactant such asa sorbitan fatty acid ester, a glycerin fatty acid ester, a fatty acidpolyglyceride, a fatty acid alcohol polyglycol ether, acetylene glycol,acetylene alcohol, an oxyalkylene block polymer, a polyoxyethylene alkylether, a polyoxyethylene alkylaryl ether, a polyoxyethylene styrylarylether, a polyoxyethylene glycol alkyl ether, polyethylene glycol, apolyoxyethylene fatty acid ester, a polyoxyethylene sorbitan fatty acidester, a polyoxyethylene glycerin fatty acid ester, a polyoxyethylenehydrogenated castor oil or a polyoxypropylene fatty acid ester; avegetable oil or mineral oil such as olive oil, kapok oil, castor oil,palm oil, camellia oil, coconut oil, sesame oil, corn oil, rice branoil, peanut oil, cottonseed oil, soybean oil, rapeseed oil, linseed oil,tung oil or liquid paraffins; and a transesterified vegetable oil suchas methylated rapeseed oil or ethylated rapeseed oil. These additivesmay suitably be selected for use alone or in combination as a mixture oftwo or more of them, so long as the object of the present invention ismet. Further, additives other than the above-mentioned may be suitablyselected for use among those known in this field. For example, variousadditives commonly used, such as a filler, a thickener, an anti-settlingagent, an anti-freezing agent, a dispersion stabilizer, a safener, ananti-mold agent, a bubble agent, a disintegrator and a binder, may beused. The mix ratio by weight of the active ingredients to such variousadditives in the herbicidal composition of the present invention may befrom 0.001:99.999 to 95:5, preferably from about 0.005:99.995 to about90:10.

As a method of applying the herbicidal composition of the presentinvention, a proper method can be employed among various methodsdepending upon various conditions such as the application site, the typeof the formulation, and the type and the growth stage of the undesiredplants to be controlled.

For example, the following methods may be mentioned.

(1) Compound A, compound B and compound C are separately formulated, andthe formulations are applied to plants to be controlled as they are oras diluted to predetermined concentrations with e.g. water as the caserequires, and as the case requires, as mixed with a spreader (such as asurfactant, a vegetable oil or a mineral oil).

(2-1) Compound A and compound B are formulated together, and compound Cis formulated, and the formulations are applied to plants to becontrolled as they are or as diluted to predetermined concentrationswith e.g. water, and as the case requires, as mixed with a spreader(such as a surfactant, a vegetable oil or a mineral oil).

(2-2) Compound A and compound C are formulated together, and compound Bis formulated, and the formulations are applied to plants to becontrolled as they are or as diluted to predetermined concentrationswith e.g. water, and as the case requires, as mixed with a spreader(such as a surfactant, a vegetable oil or a mineral oil).

(2-3) Compound B and compound C are formulated together, and compound Ais formulated, and the formulations are applied to plants to becontrolled as they are or as diluted to predetermined concentrationswith e.g. water, and as the case requires, as mixed with a spreader(such as a surfactant, a vegetable oil or a mineral oil).

(3) Compound A, compound B and compound C are formulated together, andthe formulation is applied to plants to be controlled as it is or asdiluted to a predetermined concentration with e.g. water, and as thecase requires, as mixed with a spreader (such as a surfactant, avegetable oil or a mineral oil).

In the above application methods (1) and (2-1) to (2-3), the respectiveformulations may be mixed when diluted to predetermined concentrationswith e.g. water so that they are applied to plants to be controlledsimultaneously, or they may be applied continuously or with anappropriate interval. In order to obtain effects of the presentinvention more effectively, it is preferred to apply compound A,compound B and compound C simultaneously.

Preferred embodiments of the present invention will be described below,but the present invention is by no means restricted thereto.

(1) A herbicidal composition comprising (a) nicosulfuron or its salt,(b) prosulfuron or its salt and (c) at least one herbicidal compoundselected from the group consisting of mesotrione, bicyclopyrone,dicamba, dicamba ester, bromoxynil, bromoxynil ester and their salts.

(2) The herbicidal composition according to the above (1), whichcontains (a), (b) and (c) in amounts to show a herbicidally synergisticeffect (synergistic herbicidally effective amount).

(3) The herbicidal composition according to the above (1), wherein theweight ratio of (a) to (b) is within a range of from 75:1 to 1:15, andthe weight ratio of (a) to (c) is within a range of from 15:1 to 1:100.

(4) The herbicidal composition according to the above (1), wherein theweight ratio of (a) to (b) is within a range of from 40:1 to 1:5, andthe weight ratio of (a) to (c) is within a range of from 4:1 to 1:50.

(5) The herbicidal composition according to the above (1), whichcontains, as herbicidal compounds (herbicidally active ingredients),only (a), (b) and (c).

(6) The herbicidal composition according to the above (5), whichcontains only (a), (b) and (c) and an additive for formulation whichdoes not have a herbicidal effect by itself.

(7) The herbicidal composition according to the above (5), wherein theadditive for formulation is at least one member selected from the groupconsisting of a surfactant, a carrier, a solvent, a vegetable oil, amineral oil and a transesterified vegetable oil.

(8) A method for controlling undesired plants or inhibiting theirgrowth, which comprises a herbicidally effective amount of a herbicidalcomposition comprising (a), (b) and (c), to the undesired plants or to aplace where they grow.

(9) A method for controlling undesired plants or inhibiting theirgrowth, which comprises applying a herbicidally effective amount of (a),a herbicidally effective amount of (b) and a herbicidally effectiveamount of (c) to the undesired plants or to a place where they grow.

(10) The method according to the above (8) or (9), wherein the undesiredplants are weeds having lowered sensitivity to herbicidal compounds.

(11) The method according to the above (8) or (9), wherein the undesiredplants are weeds having lowered sensitivity to ALS (acetolactatesynthase) inhibitors.

(12) The method according to the above (8) or (9), which comprisesapplying (a) in an amount to show a herbicidally synergistic effect(synergistic herbicidally effective amount), (b) in an amount to show aherbicidally synergistic effect (synergistic herbicidally effectiveamount) and (c) in an amount to show a herbicidally synergistic effect(synergistic herbicidally effective amount).

(13) The method according to the above (8) or (9), wherein (a) isapplied in an amount of from 5 to 150 g/ha, (b) is applied in an amountof from 2 to 75 g/ha, and (c) is applied in an amount of from 10 to 500g/ha.

(14) The method according to the above (8) or (9), wherein (a) isapplied in an amount of from 10 to 100 g/ha, (b) is applied in an amountof from 2.5 to 50 g/ha, and (c) is applied in an amount of from 25 to500 g/ha.

(15) The method according to the above (8) or (9), wherein theapplication is for soil treatment.

(16) The method according to the above (8) or (9), wherein the undesiredplants are strongly noxious weeds in corn fields.

(17) The method according to the above (8) or (9), wherein the undesiredplants are weeds in a stage before emergence to 8-leaf stage.

(18) The method according to the above (8) or (9), wherein the undesiredplants are annual or perennial gramineae.

(19) The herbicidal composition according to the above (1), wherein (c)is at least one herbicidal compound selected from the group consistingof bicyclopyrone, dicamba, dicamba ester, bromoxynil, bromoxynil esterand their salts.

(20) The herbicidal composition according to the above (1), wherein (c)is at least one herbicidal compound selected from the group consistingof mesotrione, bicyclopyrone and their salts.

(21) The herbicidal composition according to the above (1), wherein (c)is at least one herbicidal compound selected from the group consistingof bromoxynil, bromoxynil ester and their salts.

(22) The herbicidal composition according to the above (1), wherein (c)is mesotrione or its salt.

(23) A herbicide against convolvulaceae, solanaceae, gramineae,lequminosae, compositae or malvaceae, which comprises (a), (b) and (c)as defined in the above (1).

(24) A herbicide against convolvulaceae or solanaceae, which comprises(a), (b) and (c) as defined in the above (1).

(25) The herbicidal composition according to the above (1), which isused to control convolvulaceae, solanaceae, qramineae, leguminosae,compositae or malvaceae, or to inhibit their growth.

(26) The herbicidal composition according to the above (1), which isused to control convolvulaceae or solanaceae, or to inhibit theirgrowth.

(27) A method for controlling undesired plants or inhibiting theirgrowth, which comprises applying a herbicidally effective amount of (a)nicosulfuron or its salt, a herbicidally effective amount of (b)prosulfuron or its salt and a herbicidally effective amount of (c) atleast one herbicidal compound selected from the group consisting ofmesotrione, bicyclopyrone, dicamba, dicamba ester, bromoxynil,bromoxynil ester and their salts, to the undesired plants or to a placewhere they grow.

(28) The method according to the above (27), wherein the undesiredplants are convolvulaceae, solanaceae, gramineae, leguminosae,compositae or malvaceae.

(29) The method according to the above (27), wherein the undesiredplants are convolvulaceae or solanaceae.

(30) The method according to the above (27), wherein the undesiredplants are annual or perennial qramineae.

EXAMPLES

Now, the present invention will be described in detail with reference tothe following Examples. However, it should be understood that thepresent invention is by no means restricted thereto.

In Test Examples, as nicosulfuron, a flowable containing nicosulfuron asan active ingredient (tradename: ONEHOPE NYUZAI, manufactured byIshihara Sangyo Kaisha, Ltd.) was used.

As prosulfuron, water dispersible granules containing prosulfuron as anactive ingredient (tradename: Peak, manufactured by Syngenta) were used.

As mesotrione, a flowable containing mesotrione as an active ingredient(tradename: Callisto, manufactured by Syngenta) was used.

As dicamba, water dispersible granules containing dicamba as an activeingredient (tradename: Celebrity B, manufactured by BASF) were used.

As bicyclopyrone, a wettable powder containing bicyclopyrone prepared bya conventional method was used.

As bromoxynil-octanoate, an emulsifiable concentrate containingbromoxynil-octanoate as an active ingredient (tradename: Certrol B,manufactured by Bayer CropScience) was used.

Test Example 1

Upland field soil was put into a 1/300,000 ha pot, and seeds ofsunn-hemp (Crotalaria juncea L.) were sown. On the next day,predetermined amounts of the above formulations respectively containingnicosulfuron, prosulfuron and mesotrione were diluted with water (in anamount corresponding to 1,000 L/ha) and applied for soil treatment by asmall sprayer.

On the 28th day after treatment, the state of growth of the sunn-hempwas visually observed to determine the growth inhibition rate (%) inaccordance with the following evaluation standard. The growth inhibitionrate (%) (measured value) and the growth inhibition rate (%) (calculatedvalue) calculated by the Colby's formula are shown in Table 1.Growth inhibition rate (%)=0 (equivalent to the non-treated area) to 100(complete kill)

TABLE 1 Growth inhibition rate of sunn-hemp (%) Dose Measured CalculatedCompound (g/ha) value value Nicosulfuron 10 30 — Prosulfuron 50 60 —Mesotrione 150 30 — Nicosulfuron + 10 + 50 + 150 100 80 Prosulfuron +Mesotrione

Test Example 2

Upland field soil was put into a 1/300,000 ha pot, and seeds of wild oat(Avena fatua L.) were sown. On the next day, predetermined amounts ofthe above formulations respectively containing nicosulfuron, prosulfuronand mesotrione were diluted with water (in an amount corresponding to1,000 L/ha) and applied for soil treatment by a small sprayer.

On the 28th day after treatment, the state of growth of the wild oat wasvisually observed to determine the growth inhibition rate (%). Thegrowth inhibition rate (%) (measured value) and the growth inhibitionrate (%) calculated in the same manner as in the above Test Example 1are shown in Table 2.

TABLE 2 Growth inhibition rate of wild oat (%) Dose Measured CalculatedCompound (g/ha) value value Nicosulfuron 100 80 — Prosulfuron 2.5 0 —Mesotrione 25 0 — 150 0 — Nicosulfuron + 100 + 2.5 + 25 90 80Prosulfuron + 100 + 2.5 + 150 85 80 Mesotrione

Test Example 3

Upland field soil was put into a 1/300,000 ha pot, and seeds of wild oat(Avena fatua L.) were sown. On the next day, predetermined amounts ofthe above formulations respectively containing nicosulfuron, prosulfuronand mesotrione were diluted with water (in an amount corresponding to1,000 L/ha) and applied for soil treatment by a small sprayer.

On the 28th day after treatment, the state of growth of the wild oat wasvisually observed to determine the growth inhibition rate (%). Thegrowth inhibition rate (%) (measured value) and the growth inhibitionrate (%) calculated in the same manner as in the above Test Example 1are shown in Table 3.

TABLE 3 Growth inhibition rate of wild oat (%) Dose Measured CalculatedCompound (g/ha) value value Nicosulfuron 30 70 — Prosulfuron 15 0 —Mesotrione 50 0 — Nicosulfuron + 30 +15 + 50 80 70 Prosulfuron +Mesotrione

Test Example 4

Upland field soil was put into a 1/300,000 ha pot, and seeds of pricklysida (Sida spinosa L.) were sown. On the next day, predetermined amountsof the above formulations respectively containing nicosulfuron,prosulfuron, dicamba and bicyclopyrone were diluted with water (in anamount corresponding to 1,000 L/ha) and applied for soil treatment by asmall sprayer.

On the 28th day after treatment, the state of growth of the prickly sidawas visually observed to determine the growth inhibition rate (%). Thegrowth inhibition rate (%) (measured value) and the growth inhibitionrate (%) calculated in the same manner as in the above Test Example 1are shown in Table 4.

TABLE 4 Growth inhibition rate of prickly sida (%) Dose MeasuredCalculated Compound (g/ha) value value Nicosulfuron 10 10 — 30 10 — 10020 — Prosulfuron 2.5 20 — 15 20 — 50 40 — Dicamba 50 0 — 150 20 — 400 40— Bicyclopyrone 25 25 — Nicosulfuron + 10 + 50 + 50 100 46 Prosulfuron +10 + 50 + 400 100 68 Dicamba 100 + 2.5 + 50 50 36 100 + 2.5 + 400 100 6230 + 15 + 150 100 42 Nicosulfuron + 10 + 50 + 25 99 60 Prosulfuron +100 + 2.5 + 25 70 52 Bicyclopyrone

Test Example 5

Upland field soil was put into a 1/300,000 ha pot, and seeds of blacknightshade (Solanum nigrum L.) were sown. On the next day, predeterminedamounts of the above formulations respectively containing nicosulfuron,prosulfuron and bromoxynil-octanoate were diluted with water (in anamount corresponding to 1,000 L/ha) and applied for soil treatment by asmall sprayer.

On the 28th day after treatment, the state of growth of the blacknightshade was visually observed to determine the growth inhibition rate(%). The growth inhibition rate (%) (measured value) and the growthinhibition rate (%) calculated in the same manner as in the above TestExample 1 are shown in Table 5.

TABLE 5 Growth inhibition rate of black nightshade (%) Dose MeasuredCalculated Compound (g/ha) value value Nicosulfuron 10 20 — Prosulfuron50 20 — Bromoxynil-octanoate 100 0 — 500 0 — Nicosulfuron + 10 + 50 +100 83 36 Prosulfuron + 10 + 50 + 500 93 36 Bromoxynil-octanoate

Test Example 6

Upland field soil was put into a 1/300,000 ha pot, and seeds of annualragweed (Ambrosia artemisiifolia L.) were sown. On the next day,predetermined amounts of the above formulations respectively containingnicosulfuron, prosulfuron and bromoxynil-octanoate were diluted withwater (in an amount corresponding to 1,000 L/ha) and applied for soiltreatment by a small sprayer.

On the 28th day after treatment, the state of growth of the annualragweed was visually observed to determine the growth inhibition rate(%). The growth inhibition rate (%) (measured value) and the growthinhibition rate (%) calculated in the same manner as in the above TestExample 1 are shown in Table 6.

TABLE 6 Growth inhibition rate of annual ragweed (%) Dose MeasuredCalculated Compound (g/ha) value value Nicosulfuron 30 0 — 100 0 —Prosulfuron 2.5 78 — 15 93 — Bromoxynil-octanoate 100 0 — 200 0 — 500 0— Nicosulfuron + 100 + 2.5 + 100 99 78 Prosulfuron + 100 + 2.5 + 500 10078 Bromoxynil-octanoate 30 + 15 + 200 100 93

Test Example 7

Upland field soil was put into a 1/300,000 ha pot, and seeds ofivy-leaved morningglory (Ipomoea hederacea (L.) Jacq.) were sown. On thenext day, predetermined amounts of the above formulations respectivelycontaining nicosulfuron, prosulfuron and bicyclopyrone were diluted withwater (in an amount corresponding to 1,000 L/ha) and applied for soiltreatment by a small sprayer.

On the 14th day after treatment, the state of growth of the ivy-leavedmorningglory was visually observed to determine the growth inhibitionrate (%). The growth inhibition rate (%) (measured value) and the growthinhibition rate (%) calculated in the same manner as in the above TestExample 1 are shown in Table 7.

TABLE 7 Growth inhibition rate of ivy-leaved morningglory (%) DoseMeasured Calculated Compound (g/ha) value value Nicosulfuron 10 0 —Prosulfuron 50 50 — Bicyclopyrone 25 5 — 400 25 — Nicosulfuron + 10 +50 + 25 88 53 Prosulfuron + 10 + 50 + 400 100 63 Bicyclopyrone

Test Example 8

Upland field soil was put into a 1/300,000 ha pot, and seeds of koreanlespedeza (Kummerowia stipulacea (Maxim.) Makino) were sown. On the nextday, predetermined amounts of the above formulations respectivelycontaining nicosulfuron, prosulfuron and bicyclopyrone were diluted withwater (in an amount corresponding to 1,000 L/ha) and applied for soiltreatment by a small sprayer.

On the 28th day after treatment, the state of growth of the koreanlespedeza was visually observed to determine the growth inhibition rate(%). The growth inhibition rate (%) (measured value) and the growthinhibition rate (%) calculated in the same manner as in the above TestExample 1 are shown in Table 8.

TABLE 8 Growth inhibition rate of korean lespedeza (%) Dose MeasuredCalculated Compound (g/ha) Value value Nicosulfuron 100 30 — Prosulfuron2.5 50 — Bicyclopyrone 400 78 — Nicosulfuron + 100 + 2.5 + 400 98 92Prosulfuron + Bicyclopyrone

Test Example 9

Upland field soil was put into a 1/1,000,000 ha pot, and seeds of annualragweed (Ambrosia artemisiifolia L.) were sown. When the annual ragweedreached 6.0 to 8.0-leaf stage, predetermined amounts of the aboveformulations respectively containing nicosulfuron, prosulfuron andmesotrione were diluted with water (in an amount corresponding to 300L/ha) and applied for foliar treatment by a small sprayer.

On the 14th day after treatment, the state of growth of the annualragweed was visually observed to determine the growth inhibition rate(%). The growth inhibition rate (%) (measured value) and the growthinhibition rate (%) calculated in the same manner as in the above TestExample 1 are shown in Table 9.

TABLE 9 Growth inhibition rate Dose of annual ragweed (%) Compound(g/ha) Measured value Calculated value Nicosulfuron 30 0 — Prosulfuron10 55 — 15 53 — Mesotrione 75 25 — Nicosulfuron + 30 + 10 + 75 73 66Prosulfuron + 30 + 15 + 75 76 64 Mesotrione

Test Example 10

Upland field soil was put into a 1/1,000,000 ha pot, and seeds of commonlespedeza (Lespedeza striata (Thunb.) Hook. et Arn.) were sown. When thecommon lespedeza reached 4.0-leaf stage, predetermined amounts of theabove formulations respectively containing nicosulfuron, prosulfuron anddicamba were diluted with water (in an amount corresponding to 300 L/ha)and applied for foliar treatment by a small sprayer.

On the 14th day after treatment, the state of growth of the commonlespedeza was visually observed to determine the growth inhibition rate(%). The growth inhibition rate (%) (measured value) and the growthinhibition rate (%) calculated in the same manner as in the above TestExample 1 are shown in Table 10.

TABLE 10 Growth inhibition rate of common lespedeza (%) Dose MeasuredCalculated Compound (g/ha) value value Nicosulfuron 30 5 — Prosulfuron10 10 — 15 13 — Dicamba 100 23 — 150 50 — Nicosulfuron + 30 + 10 + 10063 34 Prosulfuron + 30 + 15 + 100 68 36 Dicamba 30 + 10 + 150 68 57 30 +15 + 150 70 58

Test Example 11

Upland field soil was put into a 1/1,000,000 ha pot, and seeds ofvelvetleaf (Abutilon theophrasti Medic.) were sown. When the velvetleafreached 5.0 to 5.3-leaf stage, predetermined amounts of the aboveformations respectively containing nicosulfuron, prosulfuron, dicamba,bromoxynil-octanoate and bicyclopyrone were diluted with water (in anamount corresponding to 300 L/ha) and applied for foliar treatment by asmall sprayer.

On the 20th day after treatment, the state of growth of the velvetleafwas visually observed to determine the growth inhibition rate (%). Thegrowth inhibition rate (%) (measured value) and the growth inhibitionrate (%) calculated in the same manner as in the above Test Example 1are shown in Table 11.

TABLE 11 Growth inhibition rate of velvetleaf (%) Dose MeasuredCalculated Compound (g/ha) value value (Nicosulfuron + (30 + 15) 55 —prosulfuron) Dicamba 150 8 — Bromoxynil-octanoate 200 5 — Bicyclopyrone100 40 — (Nicosulfuron + (30 + 15) + 63 58 prosulfuron) + 150 Dicamba(Nicosulfuron + (30 + 15) + 73 57 prosulfuron) + 200Bromoxynil-octanoate (Nicosulfuron + (30 + 15) + 83 73 prosulfuron) +100 Bicyclopyrone

By using nicosulfuron and prosulfuron and further a specific thirdcomponent in combination, a high herbicidal activity and further asynergistic effect were obtained as compared with use of nicosulfuronand prosulfuron in combination.

INDUSTRIAL APPLICABILITY

According to the present invention, a herbicidal composition having abroad herbicidal spectrum, having high activity and having a longlasting effect, is provided, broadening of the herbicidal spectrumparticularly against oramineae and application to genetically-modifiedcrops resistant to ALS inhabitance, etc. are possible, and an increasein the application site can be expected.

Further, the present invention can meet requirements by practical usersthat development of resistance is to be delayed by use of activeingredients differing in the mechanism in combination, against weedswhich have acquired resistance due to repeated application of a specificherbicide.

The entire disclosure of Japanese Patent Application No. 2012-107101filed on May 8, 2012 including specification, claims and summary isincorporated herein by reference in its entirety.

The invention claimed is:
 1. A herbicidal composition comprising (a)nicosulfuron or its salt, (b) prosulfuron or its salt and (c) mesotrioneor its salt, wherein the mixing ratio of (a) to (b) is from 75:1 to 1:15by the weight ratio, and the mixing ratio of (a) to (c) is from 15:1 to1:100 by the weight ratio wherein combination of a, b and c exhibitssynergy in comparison to a, b or c used individually.
 2. The herbicidalcomposition according to claim 1, effective in controllingconvolvulaceae, solanaceae, gramineae, leguminosae, compositae, ormalvaceae, or inhibiting their growth.
 3. The herbicidal compositionaccording to claim 1, wherein the mixing ratio of (a) to (c) is from 4:1to 1:15 by the weight ratio.
 4. A method for controlling undesiredplants or inhibiting their growth, which comprises applying aherbicidally effective amount of (a) nicosulfuron or its salt, aherbicidally effective amount of (b) prosulfuron or its salt, and aherbicidally effective amount of (c) mesotrione or its salt, to theundesired plants or to a place where they grow, wherein (a) is appliedin an amount of from 5 to 150 g/ha, (b) is applied in an amount of from2 to 75 g/ha, and (c) is applied in an amount of from 10 to 500 g/ha;wherein the applying of a, b and c together exhibits synergy incomparison to applying a, b or c individually.
 5. The method accordingto claim 4, wherein the undesired plants are strongly noxious weeds incorn fields.
 6. The method according to claim 4, wherein the undesiredplants are weeds having lowered sensitivity to herbicidal compounds. 7.The method according to claim 4, wherein the undesired plants are weedsin a stage before emergence to 8-leaf stage.
 8. The method according toclaim 4, wherein the undesired plants are convolvulaceae, solanaceae,gramineae, leguminosae, compositae, or malvaceae.
 9. The methodaccording to claim 4, wherein the undesired plants are convolvulaceae orsolanaceae.
 10. The method according to claim 4, wherein the undesiredplants are annual or perennial gramineae.
 11. The method according toclaim 4, wherein the (c) is applied in an amount of from 25 to 150 g/ha.12. The method according to claim 4, wherein the undesired plant isvelvet leaf.